A battery is an electro-chemical device that converts chemical energy into electrical energy. A battery generally includes an anode and a cathode, which are connected by an electrolyte. The electrolyte can be a wet electrolyte or a dry electrolyte that is activated by moisture. When the battery is in operation, a redox reaction occurs. During the redox reaction, reduction occurs to cations at the cathode and oxidization occurs to anions at the anode. The battery has a terminal voltage, which is measured as the difference of voltage between the anode and cathode.